I have a 1961 Chev 348 with Rochester 4GC carb on it. I have had the carb rebuilt several times and it is now about ready for replacement.. I want something around 600 cfm. I don't want to change the intake manifold. Car has a TH350 transmission. I know I will need a spacer to adapt the new carburetor. I also want to be able to use my stock air cleaner. I probably want an electric choke.. Also concern about vacuum hose for distributor vacuum advance. What carburetor would be a suitable candidate ?